Moving upstream in the frailty trajectory

Frailty is a condition characterised by loss of biological reserves and vulnerability to a range of adverse outcomes[1, 2].The cumulative deficit and phenotype models of frailty are internationally established and validated, but both models mainly use performance-based or clinical and functional assessments to identify frailty[3, 4]. This approach provides an important framework around which to understand frailty, but consideration of frailty from a physiological approach may enable improved precision of diagnosis, including identification of subclinical frailty, allowing future upstream targeting of interventions. Efforts to identify subclinical frailty from a biological perspective are aligned with a life course approach to frailty[5], which may enable investigation of clustering of characteristics at different life stages, and help shape future health policy.